For an insider's view of the talks, I was fortunate to meet Brazil's special ambassador for climate change, Sergio Serra, during a recent trip to Brasilia. We spoke on the same day as the news came from the US Senate, so I emailed him after for his reaction. He thinks the next big meeting, in Cancún, Mexico, a year after the Copenhagen summit, is now dead as far as setting targets to cut greenhouse gases – aka mitigation – are concerned. He said:

"As for the (bad) news from the US Senate, they are not that surprising. Of course, this will affect the negotiations: We will definitely not be able to close a deal in Cancún, at least not a complete deal as regards mitigation targets, because most of the other developed countries will only commit to a final figure once they know what the US's is going to be. But we hope we can still reap some "deliverables" in Cancun, such as the fast-track financing."

The money, for Serra, is the key:

"Most important is the financing. The
fast-track financing, which is a very positive development, is on three years [2010-2012] – one of those years is already here. It will be a very interesting step towards rebuilding confidence, if we have a commitment on fast-track financing. Some countries say the [
proposed deal] is unambitious, the $30bn over three years. It won't save climate change in developing countries but it's a good start, especially for adaptation. By 2020,
financing is expected to be $100-200bn a year. The G77 [negotiating group of developing countries] want a much bigger figure than this – 1-1.5% of GDP - but this will never materialise. The figures that are there now are not bad."

The Cancún meeting in November also hopes to make progress on combatting deforestation. That's a topic very close to the heart of Brazil, home of the Amazon rainforest, where the destruction has been falling recently. But Serra said he didn't expect Brazil to benefit as much as others from the funds aimed at making trees worth more alive than dead - a scheme known as Reducing Emissions from Deforestation and Forest Degradation (Redd).

"If you are talking about money, of course it will help us [reduce deforestation]. But personally, I think whatever money comes from the
Redd scheme, grants, public funds, markets, it will mostly go to poorer countries with tropical forests like Congo. I am talking realistically. And even if no money comes from Redd, President Lula said in Copenhagen that we would do it ourselves anyway."

Serra does add wryly that Lula's comment was "off-the cuff", not what we in the UK might call a "costed promise". Perhaps inevitably for a diplomat, he sees the falling public interest in the talks as both good and bad.

"There were huge expectations [in Copenhagen], almost irrationally huge. The focus of the media and public in the negotiations, the fact is that has diminished. So that it is good as there is not so much pressure, but if there is no pressure from public opinion, the conference will not deliver as much."

We also talked about whether Brazil is a developing country. That is crucial as the UNFCCC talks splits nations into developed and developing countries, with firm obligations on the former but not the latter.

But he acknowledges that things will change in the future. "Of course this is a dynamic thing – China will overtake us, but they will have much less historical responsibility."

He also chides the US over what he sees as double standards on the "monitoring, reporting and verification" of pledges to cut emissions. "The US is pressuring countries like Brazil, India, China and South Africa much more on MRV than they will apply to themselves. Their numbers have to be accounted for internationally, just as our actions will be."

"One bad consequence of the Copenhagen accord was some people saw it as an undemocratic result. Five or six countries were very vocal, 120+ have signed the accord, but still 60-70 have not signed. We do not think the Accord is the real answer, it is a step. We will get nowhere unless we focus on getting a transparent and inclusive process.

Serra then gives an insight into the mind-bending nature of international diplomacy:

"It is a big challenge to get a consensus. But consensus is not exactly the same as unanimity, you only can't be opposed. Countries can contribute to the consensus by their silence. Consensus provides a legitimacy for the results, we are talking here of a very complex thing, climate."